Bruce Beresford-Redman speaks out from prison

Bruce Beresford-Redman is speaking out for the first time since he was sent back to Mexico to face charges that he murdered his wife in 2010.

"This is the first time I've chosen to speak," Beresford-Redman said. "Everyone seems to have decided a long time ago that I killed my wife. I didn't kill my wife, I really didn't."

"I can't imagine how anyone who listened to everything said could possibly think I had anything to do with killing my wife," he added.

Beresford-Redman , the TV reality producer whose past credits include "Survivor" and "The Contender" sits in a jail cell in Cancun, accused of murdering his 42-year-old wife Monica. He was extradited from the U.S. two and a half weeks ago.

A CBS News interview with the former TV producer will air exclusively tomorrow night on "48 Hours Mystery." The interview was shot by a "48 Hours Mystery" producer on a cell phone just days ago.

Beresford-Redman is suspected by Monica's family, especially after he defied Mexican authorities, fled to the U.S. and went about his life as he fought extradition. Arrested as a flight risk, he spent 15 months in a Los Angeles jail before being returned to Mexico for trial.

For more on the case, watch Bill Whitaker's report in the video below.

In 2010, Beresford-Redman and his wife Monica were on vacation with their two young children at the Moon Palace, a luxury resort in Cancun, trying to patch up a troubled marriage. His wife had discovered he had been having an affair.

"It was her birthday. It was a family trip," Beresford-Redman told CBS News. "And we just said, 'Look, let's just go and have a good time,' and that was it."

Beresford-Redman said Monica went out shopping one morning and never returned. Mexican authorities say he strangled her and dumped her body in a sewer.

"...They claim that in one hotel room with my two small children that I killed her and then I left her in a room all day long, while my children and I went in and out," Beresford-Redman said. "All the while, Monica's dead body is supposedly in the room. It's ludicrous and it's also completely false."

Monica's family believes it's all true. Jeane Burgos, Monica's sister, told "CBS News," "I said, 'Bruce, where is my sister,' and it was almost like he mocked me. He said, 'I don't know.' It was horrible experience."

Mexican prosecutors feel they have a strong case. Bruce had scratches on his hands and feet, which he claims he got at water park with his kids. People in a nearby hotel room thought they heard a woman screaming for help.

Beresford-Redman claims that people in that hotel room heard his son and daughter. "What they heard in fact was my son and daughter squealing and laughing and playing and roughhousing," he said.

Prosecutors contend Beresford-Redman had reason to kill his wife: he was having an affair, they say; he wanted sole custody of his two children; and there was insurance money to collect. No trial date has been set.

"48 Hours Mystery" correspondent Troy Roberts said his producers obtained the interview on a visiting day at the jail.

"The arrangement they have on visiting day (at the jail) is so bizarre," Roberts said. "Typically they'll bring inmates down to a common area to meet with family or speak to them behind glass. But in this case, they opened up all the cell doors in the cell block and people went in unescorted, bringing food and their children, and they just like wandered around the room. Our producers were there for three hours. They spoke to him for 30 minutes with the cell phone and not a single guard came in and said anything to them. It was just absolutely strange."

"My producer went through three checkpoints," Roberts said. "He went through a metal detector and they did not find a cell phone."

The irony of a top reality show producer caught in a real-life murder mystery is not lost on Beresford-Redman.

He said, "Am I a survivor or not? I think very much (that) remains to be seen."

You can watch the full report on "48 Hours Mystery" on Saturday at 10 p.m./9c on CBS.

To watch Troy Roberts' preview report, watch the video in the player above.